export const stepInt = (
  value: number,
  action: string = '+',
  step: number = 1
): number => {
  let v: number = 0 // 原来的值。
  if (action == '+') {
    v = Math.floor(value + step)
  } else if (action == '-') {
    v = Math.floor(value - step)
    if (v < 0) {
      v = 0
    }
  }
  return v
}
